Hyperemesis gravidarum and maternal cancer risk, a scandinavian nested case‐control study

Abstract

Reproductive factors have been shown to influence cancer risk. Several pathological conditions during pregnancy have also been associated with subsequent altered cancer risk in the mother. Hyperemesis gravidarum (hyperemesis) is an early pregnancy condition characterized by severe nausea and vomiting resulting in weight loss and metabolic disturbances. Studies have reported associations between hyperemesis and cancer, but results are inconsistent. In this nested case-control study we linked the population-based medical birth registries and cancer registries in Norway, Sweden and Denmark in order to examine overall cancer risk and risk of specific cancer types in women with a history of hyperemesis, using conditional logistic regression. In total, 168,501 cases of cancer in addition to up to 10 cancer-free controls per case were randomly sampled, matched on year of birth and birth registry (n 5 1,721,626). Hyperemesis was defined through the International Classification of Diseases. Analyses were adjusted for potential confounders. Hyperemesis was inversely associated with overall cancer risk with adjusted relative risk (aRR) of 0.93 (95% CI: 0.88-0.99), with cancer in the lungs (aRR: 0.60, 95% CI: 0.44-0.81), cervix (aRR: 0.66, 95% CI: 0.49-0.91) and rectum (aRR: 0.48, 95% CI: 0.29-0.78). Thyroid cancer was positively associated with hyperemesis (aRR 1.45, 95% CI: 1.06-1.99) and risk increased with more than one hyperemetic pregnancy (aRR 1.80, 95% CI: 1.23-2.63). Hormonal factors, in particular human chorionic gonadotropin, are likely to be involved in mediating these effects. This study is the first to systematically address these associations and provides valuable knowledge on potential long-term consequences of hyperemesis.Factors related to pregnancy including maternal age, parity and use of assisted reproductive techniques, have been shown to influence maternal cancer risk. 1-3 Also pregnancy related conditions have been associated with subsequent maternal cancer risk, such as preeclampsia and pregnancy related hypertension with reduced risk of breast cancer in several studies. 4,5 Hyperemesis gravidarum (hyperemesis), characterized by intractable nausea and vomiting in early pregnancy resulting in maternal weight loss, metabolic and electrolyte disturbances, 6 may also be associated with breast cancer, 7,8 but the results of studies have so far been inconsistent.Hyperemesis is likely related to altered hormonal levels such as human chorionic gonadotropin (hCG) and estrogen. 9 Studies have demonstrated that molar pregnancy, female or

Breast cancer risk in relation to history of preeclampsia and hyperemesis gravidarum: Prospective analysis in the Generations Study

“…We found, however, that women who had experienced hyperemesis during any of their pregnancies had similar breast cancer risk overall to women who did not, at both premenopausal and postmenopausal ages. This is contrary to results from a case–control study reporting a positive association after a recent hyperemetic pregnancy in premenopausal women and one reporting inverse associations, but accords with several other studies . The prevalence of reported hyperemesis in our study (28.7%) was much higher than in surveys of prevalence of this condition (e.g., 0.3–3%).…”

“…This is contrary to results from a case-control study reporting a positive association after a recent hyperemetic pregnancy in premenopausal women 24 and one reporting inverse associations, 14 but accords with several other studies. 13,[20][21][22][23] The prevalence of reported hyperemesis in our study (28.7%) was much higher than in surveys of prevalence HR: hazard ratio; CI: confidence interval. *Reference group 5 never hyperemesis.…”

“…It has been hypothesised that it could be associated with a raised risk of maternal breast cancer via elevated estradiol levels in pregnancy. 19 The few past studies have not consistently shown an association of hyperemesis with breast cancer risk, 13,14,[20][21][22][23][24] but all except one 13 have been of case-control design, which could be prone to recall bias.…”

Immunology of hepatic diseases during pregnancy

“…The latter is based on lower insulin sensitivity. There is no evidence for an increased cancer risk, although maternal thyroid cancer was positively associated with HG [176][177][178].…”

Hyperemesis gravidarum and long‐term mortality: a population‐based cohort study

“…Some studies have reported an association between HG and risk of autoimmune disease later in life 23, 24. A recent study investigating cancer risk after HG exposure reported an inverse association between HG and overall cancer risk 25. The association between HG and mental health, both as a risk factor and as a consequence of HG, has been disputed 15, 26.…”